The present invention relates to air assisted alkaline cells.
Alkaline cells are well known in the art. A conventional alkaline cell employs a zinc anode, manganese dioxide as the cathode with an aqueous solution of potassium hydroxide for the electrolyte. These cells are readily available commercially for industrial and home applications.
Recently a new type of alkaline cell was disclosed by Cegasa International, a Spanish company. It is an air assisted cell employing zinc as the anode and manganese dioxide as the cathode with an aqueous solution of potassium hydroxide as the electrolyte. The cell is designed so that the positive electrode containing the manganese dioxide (MnO.sub.2) is supported about its periphery and along its full length in the cell by a perforated ribbed air distribution grid. The bottom or negative end of the cell has an insulating support which allows air to enter the cell and pass up along the outside of the supported positive electrode. When the cell is initially put into a circuit, the electro-chemical reaction depends primarily upon the presence of the manganese dioxide cathode. As the reaction progresses, and the manganese dioxide cathode is electrochemically reduced, air within the cell reoxidizes and recharges the manganese dioxide.
While the Cegasa cell does function for its intended purpose, it is a complex cell in that it requires a cathode support completely surrounding the cathode for exposing the surface of the cathode to air. Also, the interior of the cell has a complex pattern of supports and air distribution passages to allow air to enter the cell and contact the MnO.sub.2.
As mentioned previously, the Cegasa air assisted alkaline cell employs manganese dioxide as the active cathode material. There is no teaching in any of the Cegasa literature presently known to the inventor that the manganese dioxide used is anything other than conventional electrolytically deposited manganese dioxide which is typically used in alkaline cells. The Cegasa literature shows no awareness of any improvement to be gained through the use of mixtures of different types of manganese dioxide.